Flagship smartphones, from the iPhone X to Galaxy S9+, have beautiful displays. Should you cover them up with a screen protector? We break it down and explain the difference between PET, TPU, tempered glass, and nano liquid.

So yes, your screen can still be scratched, and it's probably the sand in your pocket (or bag) that's causing it. Screen protectors are not perfect—even the best ones are usually between a 7 and 8 on the Mohs scale, slightly better than Gorilla Glass—but they allow you to pop your phone in your pocket without worrying. Then, if and when the protector gets scratched, you can always replace it, keeping the actual screen immaculate when you go to resell it a few years down the line.

The Different Types of Screen Protectors

Search for "screen protector" on Amazon, and you'll likely be overwhelmed by the results. There are so many brands, types, and price points that it's enough to make your head spin. Thankfully, screen protectors can generally be broken down into a few simple types, each with their own advantages and disadvantages.

Polyethylene Terephthalate (PET)

PET is a type of plastic usually found on things like water bottles and other food containers. PET screen protectors provide the least amount of scratch- and impact-protection, but they're super cheap, light, and thin, and as a result are less visible once applied to your phone.

They also have a decently smooth feel, unlike the more durable but rubbery TPU. PET is also a bit stiff, so it can't go edge-to-edge on phones with curved screens like the iPhone. If you want to go with
PET
, I recommend Tech Armor.

Thermoplastic
Polyreuthane
(TPU)

When you think of the screen protectors of old, you're probably thinking of TPU. It's a flexible plastic that's a huge hassle to install (it involves using a spray solution and squeegeeing out lots of bubbles), doesn't feel very smooth (thanks to its almost rubbery texture), and adds an "orange peel" type glare to your phone's screen.

But it isn't without benefits: it's flexible, so it can go edge-to-edge on any phone, it has better impact protection than PET, and it has limited "self-healing" powers for small scratches. Brands like IQ Shield offer TPU at very affordable prices, while Zagg's InvisibleShield film is a bit more expensive—but comes in a fewdifferentstyles depending on the look and feel you want. Both also come with replacement warranties, as well, though Zagg's is more all-encompassing, hence the higher cost.

Tempered Glass

These are the granddaddies of screen protectors. They don't have the self-healing abilities of TPU, but they're tougher in terms of scratch- and drop-protection, and these days you can get them pretty inexpensively.

Nano Liquid

These days you'll also find liquid screen protectors on the market, which claim you can protect your phone just by swabbing a solution on your phone and then buffing it off. These protectors come with a host of quirks that make it hard to recommend. While it may provide some level of extra protection, the layer is so thin that tough scratches can likely still easily get through to the actual screen, which defeats the purpose of a screen protector.

Furthermore, you can't just take this off and swap it with another screen protector—both Spigen and Qmadix say you cannot remove the product; it will merely wear off over time (though there's no visible way to tell when). That makes it hard to test because you can't just scratch it and peel the product off—it's unclear whether you'd be scratching the protector or the screen underneath. Qmadix's protector comes with a SquareTrade-
esque
$250 warranty, which is probably where most of your money goes. But all told, I'd recommend skipping the liquid stuff.

You'll also find some hybrids between these different materials. Zagg's HDX and Sapphire protectors have the self-healing properties of TPU with a slightly smoother feel. Again, they're expensive, but Zagg's warranty at least makes the price a bit easier to swallow.

In addition, you'll find variations of the above with different "extra" features, like privacy filters (so people sitting next to you can't see your screen), anti-glare surfaces (which are "matte" so you can see the screen easier in sunlight), or smudge resistance. If any of these things are important to you, you'll want to include them in your search.

Just don't pay too much attention to the hardness rating that brands advertise—most use the ASTM hardness scale, in which the hardest pencil (9H) is softer than tempered glass, making it a useless indicator of protection. The Mohs scale—which does not use an "H"—is much more useful, though it doesn't sound as good on the box. If you're unsure about the hardness of a specific brand, Google around to see if anyone has tested it themselves with a Mohs kit.

In my opinion, most people are probably best off with a tempered glass protector: they have the smoothest feel, prevent the most damage, and are available at pretty decent prices. If you're really finicky about looks, you may like PET or TPU better (since they aren't as visible once applied to your phone), especially since films like TPU can provide self-healing edge-to-edge protection on phones with curved screens. I'd avoid the liquid protection unless you know you aren't going to use any of the others anyway, and want the warranty that Qmadix provides.

If You Want Impact Protection, Get a Case

That said, screen protection is just one piece of the puzzle. These films will help you avoid scratches and provide some impact protection, but if you're worried about dropping your phone, don't stop there: get a case. A screen protector will not protect the back of your phone, the edges, or even the corners of the screen. A good case (especially one with a "lip" over the screen) will do more for drops than any screen protector, so unless you feel lucky—or have a good insurance plan—get a case along with whatever screen protection you decide on.

About the Author

Whitson Gordon is a writer, gamer, and tech nerd who has been building PCs for 10 years. He eats potato chips with chopsticks so he doesn't get grease on his mechanical keyboard. Contact him on Twitter @WhitsonGordon.